Field of the Invention
The present invention relates to a secondary battery including a fuse for blocking a current path when an excessive short-circuit current flows through the battery and an assembled battery including a plurality of the secondary batteries.
Description of Related Art
When a short circuit occurs between a positive electrode and negative electrode of a secondary battery for some reason, an excessive short-circuit current flows through the secondary battery. A secondary battery that includes a fuse for blocking a current path on the assumption of such a case is known.
Japanese Published Unexamined Patent Application No. 2015-5492 (Patent Document 1) discloses a secondary battery including a fuse disposed outside an exterior body accommodating an electrode body formed of a positive electrode and a negative electrode.
FIG. 10 is a sectional view of part of a fuse disclosed in Patent Document 1. An opening of an exterior body 101 is sealed by a sealing body 102. An external terminal 104 is formed through the sealing body 102 and connected to an electrode sheet with a current collector 103 interposed therebetween. A plate 105 is formed on a surface of the sealing body 102 so as to be joined to the external terminal 104. A thin fuse 106 is formed in part of the plate 105.
When a short circuit occurs in the secondary battery and an excessive short-circuit current flows through the secondary battery, the fuse 106 melts due to Joule heat, blocking the current path.